Objective:

To test the hypothesis that Managed Aquifer Recharge (MAR) for stormwater harvesting is a technically feasible, socially/regulatory/environ- mentally acceptable, and economically viable option for developing new water supplies for arid Western urban ecosystems experiencing increasing population, and climate change pressures on existing water resources.

Approach:

The project integrates stormwater production and conveyance models, vadose zone/groundwater transport and fate models, and ecosystem services models within a quantitative methodology for assessing the impacts and benefits of using MAR for stormwater harvesting. This methodology will incorporate existing contaminant loading and distribution conditions, stakeholder attitudes and concerns, and changing climate pressures (warmer and wetter conditions, precipitation as rain rather than snow, limited capacity for surface water storage to replace dwindling snow pack) to support future management decisions regarding stormwater harvesting to promote public safety and ecosystem health. This interdisciplinary project has three research phases: Phase 1) Monitoring of existing, diverse Cache Valley MAR stormwater harvesting schemes, and documentation of aquifer recharge potential and contaminant (VOCs, pesticides, nutrients, metals) loading and transformation for a range of relevant field conditions for input into Phase 2; Phase 2) Integrate stormwater collection/conveyance modeling with vadose zone/groundwater fate and transport and ecosystem services modeling to predict changes in aquifer storage, groundwater and surface water flow and quality, and human health and ecosystem services resulting from changes in stormwater management that maximize stormwater harvesting; and Phase 3) Assess stakeholder (city, county and state regulatory agencies, the public, engineers and developers) attitudes and preferences concerning MAR for stormwater harvesting at the beginning and end of the project. Collaborate with stakeholders to identify, select, and evaluate outcomes of MAR stormwater harvesting scenarios assessed for Salt Lake Valley using the integrated Phase 2 modeling approach.

Expected Results:

Integrated findings from field measurement, modeling and stakeholder interactions will lead to a methodology for improving risk management and optimizing MAR for stormwater harvesting applicable to other arid western basins facing increasing water supply limitations due to population growth, climate change, and often conflicting public and ecosystem demands.

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.